Can My Computer run the vx2025???

[UberPooner]

Hi, I am REALLY interested in the monitor. i really want to get it! but the problem that i think i might have is that my pc might not perform as good on thatt monitor than with my current one. the reason being is that i run all games 1280x1024, bf2 i run everything at full settings with 2x aa. on oblivion i run it at very high settings with 2xaa. ok so if 1680x1050 resolution would be equavilant as 1280x1024. if it is, since the rez is bigger wouldnt that make my computer run slower? sorry if this is confusing an example is that if i run a game at like 600x800 it would run good but look like crap. if i moved it to 1280x1024 on a crappy computer the game would have better graphics but would run slower. so im wondering if that is going to happen from switching to the wide screen monitor. if not i was thinking of getting the VX922.

here are my specs-
asus a8n sli board
evga7800gtx
2g corshair ram
amd 4000+ processor (running at 2.5ghz)

So can you please try and help me out?
-thanks